Objective To evaluate the role of contrast-enhanced color Doppler ultrasonography with Levovist in the diagnosis of liver tumors.Methods One hundred and twenty-five patients with 126 hepatic solid lesions were examined by conventional color Doppler and contrast enhanced ultrasonography.All hepatic lesions were confirmed by pathology.Of these,79 cases with hepatocellular carcinoma,4 cases with metastatic liver carcinoma,13 cases with hemangioma,7 cases with inflammatory pseudotumor of liver,7 cases with focal nodule hyperplasia,and 15 cases with other benign lesions.The Levovist with a concentration of 400 mg/ml was injected into an antecubital vein within approximately 2 minutes.Results All hepatic solid lesions with blood supply were differently enhanced by contrast-ultrasonography (I～IV grades).The color flow signals with grade III and grade IV were detected in one malignant lesion before contrast-enhancement and in 41 malignant lesions ( 49.4%) after contrast-enhancement.The color flow signals were detected by contrast-enhanced sonography in 26 malignant lesions ( 92.8%) with no color Doppler signals and in 33 benign lesions ( 76.7%).The mean resistive index of liver cancer group was much higher than that of benign lesion group before and after contrast-enhancement.The accuracy rate for diagnosing liver tumors was raised from 66.7% (84/126) in pre-enhancement to 94.4% (119/126) in post-enhancement.Conclusions The contrast-enhanced color Doppler ultrasonography is very useful in the differential diagnosis of liver tumors.

Objective To probe the correlation between the short-axis diameter(SD) of coagulation necosis and the microwave power(P) using a new type of internally cooled microwave antenna in ex vivo and in vivo liver model.Methods Fourteen microwave ablations were performed in swine livers ex vivo and canine livers in vivo under the microwave powers of 30-90W and the durations of 10 min and 20 min, respectively.The short-axis diameter(SD) and the long-axis diameter(LD) of the coagulation were measured.The difference of SD, LD and SD/LD in swine liver ex vivo and canine liver in vivo were compared.The relationship between the SD and microwave power was analysised using linear regression model.Results Under the same conditions,the SDs and LDs of the coagulations of canine livers in vivo were smaller than those of swine livers in ex vivo (P <0.01).There was such a higher linear relationship(r = 0.96-0.99, P <0.01) between the SD of coagulation and the power in vivo liver model as the results acquired in ex vivo.Conclusions Although the blood flow decreased the SDs of the coagulation of microwave ablation in liver in vivo, but there was still a higher linear relationship between SD and microwave power.

Objective To probe the correlation between the short-axis diameter(SD) of microwave coagulation and the time(T) and/or power(P) using a new type of internally cooled microwave antenna. Methods A MTC-3 microwave apparatus with a new type of internally-cooled microwave antenna was used to coagulate a fresh porcine liver in vitro. The correlation was analyzed between the SD of coagulation necrosis and the time and/or power. Results ①Under the same power, there was high linear relationship(r= 0.94- 0.98,P

Objective To evaluate the feasibility of virtual touch tissue quantification (VTQ) for the assessment of renal allograft.Methods A total of 72 kidney recipients were examined with conventional ultrasound and VTQ after transpantation.Biopsies were performed in 34 patients,20 patients were with acute rejection (AR),14 with chronic allograft nephropathy (CAN),38 patients as control group.The peak systolic velocity (PSV) and resistance index(RI) were measured on main,infrarenal and arcuate arteries with conventional ultrasound and shear wave velocity (SWV) of the renal cortex was obtained by VTQ.All the data were compared among three groups.Results There were no significant differences of PSV between two groups.An increased RI was presented in the CAN group(P ＜0.05).The mean SWV was (2.67 ± 0.27) m/s,(2.90 ± 0.31)m/s and (2.28 ± 0.24)m/s for AR,CAN and normal group,respectively.There were significant differences of SWV among the three groups (P ＜ 0.05).Conclusions VTQ technique could provide a new method for the assessment of transplanted kidney.

Objective To investigate enhancement appearance of hepatic focal nodular hyperplasia(FNH) at real-time gray-scale contrast enhanced ultrasonography(CEUS),and evaluate the value of CEUS in the diagnosis of FNH. Methods Thirty-four patients (36 lesions) with histologically proved FNH were examined by ultrasonography. Appearance on conventional ultrasonography and the enhancement pattern on CEUS were investigated. Results Thirty-six lesions were mostly hypoechoic.39% (14/36) of lesions had peripheral hypoechogenic circle. Color Doppler flow imaging showed a asteroid-like or spoke-and-wheel pattern in 65% (20/ 31) of lesions.Three enhancement patterns were observed in the early arterial phase: whole-enhancement pattern (28%, 10/36), gushing-spring enhancement pattern (44%, 16/36), and spoke-and-wheel enhancement pattern (28%,10/36).The frequency of central scar on CEUS was 17% (6/36), and detection rate of central scar by CEUS compared with pathology was 40% (6/15).Regarding one of the features (gushing-spring enhancement, spoke-and-wheel enhancement and scar) as standard of FNH, the coincidence of CEUS in this group was 78% (28/ 36) ,which was significantly higher than that of conventional ultrasonography 28% (10/36).Conclusions CEUS can be as a important method for diagnosing FNH.

Objective To compare features between color Doppler flow imaging(CDFI) and contrast-enhanced ultrasonography(CEUS) in the diagnosis of small renal cell carcinoma(SRCC) and investigate the diagnostic value of CEUS. Methods The images of CDFI and CEUS examination were retrospectively analyzed in forty-five SRCC (≤3 cm in diameter) which were confirmed sequentially by operation and pathology. Inner echoes,boundary,dark-ring and color flow of tumors were observed by CDFI. The degree of tumor vascularity was subjectively graded from 0 to Ⅳ. Enhancement patterns and phases on uhrasonography were reviewed, including enhancement start time, peak time, wash-out time and enhancement appearances of SRCC. Results The images were observed as homogeneous or relatively homogeneous (19) and heterogeneous or relatively heterogeneous(26), clear boundaries(37, including 10 with dark-ring) and ill-defined margins(8). The tumor vascularity was showed as grade 0(5) ,grade Ⅰ (6),grade Ⅱ (14),grade Ⅲ (14),grade Ⅳ(6) on CDFI. All lesions were showed mean enhancement start time (13.84±3.80) seconds,peak time (19.49±4.73) seconds,wash-out time (26.91±5.86) seconds respectively on CEUS. All cases were observed as simultaneous wash-in(39) and gradually wash-in(6),hyperechoic(14) and isoechoic(22) and hypoechoic(9) in peak time, simultaneous wash-out (19) and rapidly wahs-out (19) and gradually wahs-out(7). After contrast medium injection, tumors were detected partly non-enhaneement or cellular enhancement (25) and pseudocapsule (20). Conclusions CEUS is effective in improving the sonographic visualization of tumoral vascularity ,internal structure and pseudocapsule. It plays an important role in the diagnosis of SRCC.

Objective To evaluate the diagnostic value of virtual touch tissue quantification (VTQ) in the diagnosis of renal allograft fibrosis.Methods The renal allografts of 82 patients with biopsies or nephrectomy were assessed by virtual touch quantification.The renal allograft fibrosis was categorized according to the 2005 updated Banff criteria for a G0～G3 grade.All the results were compared among four groups.Results The mean SWV values in G0～G3 were (2.39 ± 0.31)m/s,(2.45 ± 0.34)m/s,(2.58 ± 0.18) m/s,(3.11 ± 0.40)m/s,respectively.There were no significant differences in the mean SWV value between G0 and G1 group,or between G1 and G2 group(P ＞0.05).There were significant differences in the mean SWV value between G0～G2 and G3 group,or between G0 and G2 group(P ＜0.05).Stiffness of renal allograft was significantly correlated to the mean SWV value (Spearman r =0.671,P ＜0.001).According to the area under the ROC curve,the sensitivity and specificity of SWV (area under ROC curve =0.847,cut-off=2.64 m/s) for grade ≥G2 was 78.9％ and 79.5％ respectively.Conclusions Stiffness measured by VTQ reflects the interstitial fibrosis in renal allograft.VTQ technique might be a new tool to identify patients with chronic allograft injury.

Objective To study the value of quantitative analysis of contrast-enhanced ultrasound in diagnosing acute rejection of kidney graft.Methods Sixty-seven patients with normal kidney grafts and thirty-five patients with acute rejection were recruited.In conventional ultrasound,the peak systolic velocity (PSV) and resistance index (RI) of segmental artery and interlobar artery were measured.In quantitative analysis of contrast-enhanced ultrasound,four regions of interest including renal cortex,medulla,segmental artery and interlobar artery were drew and three parameters including rising time(RT),time to peak(TTP) and mean transit time(mTT) were obtained.In addition,the difference in RT,TTP and mTT between the renal cortex and interlobar artery,as well as medulla and interlobar artery were calculated.Results The differences of PSV in interlobar artery between the two groups were statistically significant (P ＜0.05).The time-intensity curves of the whole kidney grafts,and the difference in RT and TTP between the renal cortex and interlobar artery were statistically different between two groups (P ＜0.05).Conclasions Quantitative analysis of contrast-enhanced ultrasound proved a quantitative method for diagnosing kidney allograft acute rejection.

Objective To investigate the viability of virtual touch tissue quantification (VTQ)technique in the prediction of acute rejection in transplanted liver.Methods One hundred and eighteen patients enrolled in the study were categorized into four groups:normal control (n =31),cirrhosis ( n =29),transplanted liver with acute rejection (n =28),transplant liver without any complications (n =30).All the patients were confirmed by pathology or clinical results.The VTQ of right robe of liver was obtained by a ultrasound system with VTQ technique and the data was compared among the four groups.Results The VTQ was (1.10 ± 0.29)m/s,(1.33 ± 0.33) m/s,(1.81 ± 0.47) m/s and (2.12 ± 0.59) m/s in normal control,transplanted liver without any complications,transplanted liver with acute rejection and cirrhosis group,respectively.It was significantly different in all four groups (P＜0.01).Patients with acute rejection were associated with the increase of the VTQ values (P＜0.01).Using a cutoff of VTQ＞1.36 m/s measured in the transplanted liver for prediction of acute rejection,the sensitivity and specificity were 82.1％ and 68.2％.Conclusions VTQ technique may have some clinical value in evaluation the acute rejection in transplanted liver.

Objective To explore the potential value of contrast-enhanced ultrasonography (CEUS) in diagnosis of renal pelvic carcinoma. Methods The ultrasonogram of conventional ultrasound and CEUS were analyzed retrospectively in 22 patients of renal pelvic carcinoma proved pathologically. The size, echo, boundary and color flow signal of renal pelvic lesions were observed with conventional ultrasound. The enhancement modality and phase of tumors were also observed with CEUS, including wash-in and wash-out time, as well as the perfusion appearances. Results The maximum diameters ranged from 1.5 cm to 8.5 cm in 22 renal pelvic tumors. Conventional ultrasound detected flat mass in 7 tumors, irregular mass in 15 tumors; the same side hydronephrosis in 11 patients. Color Doppler flow imaging (CDFI) disclosed fairly rich flow signal of 5 tumors, a small amount of flow signal around tumor in 9 tumors and no-flow signal in the rest tumors. CEUS detected the cortical phase enhancement in all renal pelvic tumors, including synchronously enhancement in 8 tumors and delayed enhancement in 14 tumors. In peak time, hypoechogenicity compared to the normal renal cortex was showed in 18 tumors, hyperechogenicity in 3 tumors and isoechogenicity in 1 tumor. Fast wash-out in medulla phase was displayed in 20 tumors, isochronously wash-out in 1 tumor and delayed wash-out in 1 tumor. The diagnostic accuracy of the conventional ultrasound and CEUS was 63.64% (14/22) and 81.82% (18/22), respectively. Conclusion CEUS can depict blood flow supply and improve the diagnostic rate of renal pelvic carcinoma.